SUB-CLASS in. 
CHLOROSPERMEdE, OR GREEN ALGdE. 
Diagnosis. Plants almost always grass green ; rarely olivaceous, or lurid purple, still 
more rarely red. Propagation either by simple cell-division ; by the transformation of 
the colouring matter of the cells of the whole frond, or of some of the cells, into zoospores; 
or rarely by ordinary spores developed in proper spore-cases. Antheridia , containing 
spermatozoids, have been observed in some. Marine , or living in fresh-water streams , 
ponds , and ditches , or in damp situations. 
It is difficult, in a few words, to give such a diagnostic character of the Algas 
included in this sub-class as shall comprise all the exceptional cases. The general idea 
of the group is that it shall contain Algae of a herbaceous or grass green colour, propa- 
gated by zoospores, or by the transformation of some considerable portion of the whole 
of the endochrome into spores, without these spores being developed within proper spore- 
cases, distinct from the ordinary cells of the frond. In the great majority of these 
plants both characters are found ; but some few genera and species which agree with 
the rest in the dispersed fructification, or in being propagated by zoospores, are of a 
purple or red colour, thereby approaching the Rhodosperms in appearance ; while others 
are olivaceous, and thus seem to approach the Melanosperms. It does not appear 
to be desirable, for the mere variation in colour, to separate plants which are 
in other respects so closely allied as are the Porphyrce to the TJlvce , or the red 
Palmellacece to those of a green colour. It would be necessary, were we to remove 
these aberrant genera and species to the Rhodosperms, to construct special Orders 
to receive them, nor could we place these new Orders in the series of Orders 
as at present constructed ; but must establish for them a new division of the 
sub-class, which would be characterised by the absence of cystocarpic fruit and of 
tetraspores ; that is to say, by the absence of the fructification common to the whole of 
this sub-class. Thus it would appear that these purpurascent Algae are more removed 
from true Rhodosperms, notwithstanding the red colour of their spores, than from 
Chlorosperms ; and consequently we retain them in this division. A graver anomaly, 
as it appears to me, occurs in the genera which produce spores of the ordinary character 
(not zoospores ) contained within proper cysts. These have been removed by Endlicher 
and others to the Melanospermic sub-class ; and certainly they show a considerable 
approach to that group. But on the other hand, in the characters of their vegetation, 
in the structure, habit, colour, and general aspect of the frond they are so closely united 
to true Chlorosperms, that I am unwilling to separate them ; particularly as they do not 
seem to be equally nearly related to true Melanospermese. These exceptional genera were 
formerly included in Siphonea2,sm<]. c &TQ in this work separated under the name Dasycladece. 
B 
